OUTLINE: This is a multicenter study. Patients are stratified according to ECOG performance status (0 vs 1), tumor response to standard chemotherapy (partial response vs stable disease vs complete response), and time between completion of chemotherapy to randomization 1 month (≤1 month) vs 2 months (>1 month but ≤ 2 months) vs 3 months (> 2 months but ≤ 3 months). Patients are randomized to 1 of 2 treatment arms.